This study was designed to investigate the correlation between the expression rate of p53 and p21 proteins, c-erbB-2 oncoprotein and $TGF-{\beta}1$ and tumor prognostic factors in colon cancer including the tumor size, histological differentiation and Dukes' stage. The expression rate of p53 protein was 11.4% (4 cases) at well differentiation, 48.6% (17 cases) at moderately differentiation, and 17.1% (6 cases) at poorly differentiation. In other words, the poorer differentiation, the higher the expression rate of p53 protein (P<0.05). The expression rate of p21 protein was 17.1% (6 cases) at well differentiation, 40.0% (14 cases) at moderately differentiation, and 8.6% (3 cases) at poorly differentiation, indicating that, as the histological malignant degeneration progressed, the expression rate of p21 protein decreased distinctively (P<0.05). However, the correlation of the above mentioned proteins with tumor size and Dukes' stage was not recognized. The expression rate of c-cerbB-2 oncoprotein was 11.4% (4 cases) at well differentiation, 54.3% (19 cases) at moderately differentiation, and 17.1% (6 cases) at poorly differentiation, indicating that the poorer differentiation, the higher expression rate of c-erbB-2 oncoprotein (P<0.05). The expression rate of $TGF-{\beta}1$ was 17.1% (6 cases) at well differentiation, 48.6% (17 cases) at moderately differentiation, and 11.4% (4 cases) at poorly differentiation. As Dukes' stage progressed, the expression rate of $TGF-{\beta}1$ was 8.6% (3 cases) in stage A, 20.0% (7 cases) in stage B, 37.1 % (13 cases) in stage C, and 11.4% (4 cases) in stage D. There was a difference in expression rates between Dukes' stages (P<0.05). In 10 cases, p53 protein was positive while p21 protein was negative, and in 6 cases, p53 protein was negative whereas p21 was positive (P<0.05). Therefore, a statistically significant inverse correlation between the expression rate of p53 protein and that of p21 protein was observed. In conclusion, since there was a signigicant correlation between histological differentiation of colon cancer and the expressions of p53 and p21 proteins and c-erbB-2 oncoprotein, and between Dukes' stage and the expression of $TGF-{\beta}1$, it was conformed that the overexpression of p53 and p21 proteins, c-erbB-2 oncoprotein, and $TGF-{\beta}1$ is closely associated with the occurrence of colon cancer and its progress. Accordingly, this study may be greatly beneficial to the presumption of diagnosis, treatment and prognosis of colon cancer patients.